Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!mentor.cc.purdue.edu!pur-ee!pur-phy!murphy
From: murphy@pur-phy (William J. Murphy)
Newsgroups: comp.sys.amiga.tech
Subject: Manx 3.6 bug & DBW's ext.c
Keywords: Overflow converting to FFP format!
Message-ID: <2185@pur-phy>
Date: 24 Apr 89 02:29:04 GMT
Organization: Purdue Univ. Phys Dept, W.Lafayette, IN
Lines: 70


>#define MODULE_EXTENT
#include "ray.h"

node	    *masternp = NULL;
node	    **nppstack[100] = { &masternp,};
int	    nppsp = 0;

#ifdef MCH_AMIGA
#define	    HUGE	    ((float)1.7e+38)
#endif
#define	    curnpp	    (nppstack[nppsp])
#define	    pushnpp(npp)    (nppstack[++nppsp] = npp)
#define	    popnpp	    (nppstack[nppsp--])


>void getextent(np,re)
>node *np;
>rextent *re;
>    {
>    rextent newre;
>  
>    cv(HUGE,HUGE,HUGE,re->min);
>    cv(-HUGE,-HUGE,-HUGE,re->max);
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
>  
>    while (np) {
>	switch (np->kind) {
>	    case EXTENT : getextent(eptr(np)->sub,&newre);
>			  setextent(np,&newre);
>			  break;
>	    case SPHERE  : sphere_rextent(np,&newre); break;
>	    case TRIANGLE: triangle_rextent(np,&newre); break;
>	    case QUAD    : quad_rextent(np,&newre); break;
>	    case RING    : ring_rextent(np,&newre); break;
>	    }
>	unionrextent(re,&newre,re);
>	np = np->next;
>	}
>    }

I downloaded the dbw.zoo from bach.berkeley.eduand was trying to compile
the sources for the Amiga with Manx 3.6a and came across an error 205
which reads

  cv(HUGE, HUGE, HUGE, re->min);
                                ^
ext.c: ### : ERROR 205: :
Overflow converting to FFP format!

This section of code comes from module ext.c and is only a sample from
the complete module.
This line of code occurs 6 times in the module ext.c and each of them
generate 3 errors 205 FFP conversion overflow.  I tried to find what
the FFP HUGE is supposed to defined as, but I could not find it in my
compiler manual.  As you can see it is defined as ((float)1.7e+38) which
is the limit for single precision floating point.  

My question is this,  I am sure that someone else has compiled this
program, Have you seen this error?

If so, then what do you do?  The manual points out that errors above
200 means that there is a problem with the compiler.  Is this a 
previously reported bug with 3.6? I believe that DBW_Render was
originally compiled on Manx 3.4.

Well, I haven't given up the ghost, but I thought others may be interested.
Bill Murphy
murphy@newton.physics.purdue.edu